• 생물환경조절학회지
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• 제8권1호
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• pp.1-8
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• 1999

This study was carried out to estimate the warmed water irrigation and the warmed soil efficiency on protected cultivation of cucumber in winter season. The water of 28$^{\circ}C$ was continuously supplied for soil warming and that is $25^{\circ}C$ for warmed water irrigation. Cucumber growth was analyzed when tile soil kept up the optimum temperature in the root zone. The cucumber growth are compared with the warmed soil plots. isolated warmed soil plots and non-warmed soil plots. The cucumber growth in warmed soil plots and isolated warmed soil plots were 20~50% higher than non-warmed soil plots compare to that by the warmed irrigation. In the non-warmed soil plots, the stem diameter and the number of leaves in the warmed water irrigation plots are 10% higher than those in the normal water irrigation plots. The yields in isolated warmed soil plots were 37~38% higher than non-warmed soil plots and those in warmed soil plots were 85~96% higher than non-warmed soil plots. The fruit length, weight and diameter in warmed soil plots were 15% higher than those in the non-warmed plots.

• 한국초지조사료학회지
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• 제8권1호
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• pp.1-7
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• 1988

This experiment was carried out to determine the effect of grazing and cutting system in the seven different seed mixture plots on the dry matter yield and botanical composition from October 1983 to November 1986 at 200m above the sea level in Cheju. The results obtained are summarized as follows: 1. Dry matter yield was increased more cutting system than that of grazing system during the first and second harvest year (P<0.01), but at the third harvest year grazed plot was increased (P<0.05). 2. Three-year average dry matter yield tended to be relatively higher with tall fescue mixture plots (T4 and T7) than without tall fescue mixture plots. 3. In botanical composition of the seed mixtures, orchardgrass was observed to be more dominate in cutting system, while perennial ryegrass was increased in grazed plots. 4. Tall fescue was dominated about 70-80% at the third harvest year, in the plot of both grazing and cutting system. 5. The percentage of ladino clover was slightly increased in grazed plot compared with cutting plots. However those of alfalfa and red clover were not influenced by grazing and cutting system.

• 생물환경조절학회지
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• 제7권1호
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• pp.25-33
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• 1998

겨울철 오이 시설재배에서 태양열 시스템을 이용한 지중가온의 효과를 구명하고자 지중 40 cm에 15 mm의 PPC파이프를 130 cm이랑 에 4열 매설한 후 지중 20 cm의 지온을 $22~23^{\circ}C$로 설정한 후 1996년 11월 7일부터 1997년 1월 30일까지 일정한 온도로 유지, 관리하여 무가온구와 가온구의 지상부, 지하부 및 수량을 비교시험한 결과는 다음과 같다 1) 지중가온에 의한 지온확보는 가온구는 15~20 cm에서 $22^{\circ}C$ 정도의 평균온도를 확보할 수 있었고, 무가온구는 평균 $17~18^{\circ}C$ 정도였다 2) 정식 30일 정도에서 초기생육은 가온구가 초장, 경경, 엽수, 엽면적 등 모두 증가하였으며 특히 초장 27%, 엽수 51%, 엽면적은 150% 정도 증가하였다. 또 지상부 평균 증가율도 관행대비 가온구 증가율이 117% 정도였다. 3) 가온구의 지하부 뿌리의 생장성이 관행구에 비하여 평균 56% 정도 증가하였다 4) 과수의 수량면에서도 총과수가 무가온구 313개, 가온구 614개로 가온구가 196% 정도 증수되었다.

• 응용통계연구
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• 제12권1호
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• pp.81-81
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• 1999

A categorical data analysis system in the World Wide Web is proposed with an easy- to-use environment . This system is composed of four components. First, this system presents several graphical displays for Exploratory Data Analysis for categorical data. Second, it provides some measures of association Including dynamic graphics for mosaic plots of Hartigan and Kleiner (1981) and Friendly (1994). Dynamic graphics for mosaic plots give some useful informations. Third, this system can analyze categorical data with loglinear models. So we can select the best fitted loglinear model interactively.

• Communications for Statistical Applications and Methods
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• 제7권1호
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• pp.37-46
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• 2000

We investigate some properties of commonly used residual plots in linear regression and provide some systematic insight into the relationships among the plots. We discuss three issues of linear regression in this stream of context. First of all we introduce two graphical comparison methods to display the variance inflation factor. Secondly we show that the role of a suppressor variable in linear regression can be checked graphiclly. Finally we show that several other types of standardized regression coefficients besides the ordinary one can be obtained in residual plots and the correlation coefficients of one of these residual plots can be used in ranking the relative importance of variables.

• 한국작물학회지
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• 제47권4호
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• pp.273-278
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• 2002

An efficient low-input system (LIS) for fertiliser use in rice cultivation is necessary to reduce fossil energy use and pollution. Japanese people like Japonica rice, especially cv. Koshihikari. However, it has very low lodging resistance in Japanese weather condition. Our objective was to develop a LIS with the minimum sacrifice of grain yield in rice. Koshihikari was grown using conventional fertilization as a control (CON) with 4 g N $m^{-2}$., 8g $P_2$ $O_{5}$ $m^{-2}$ and 8 g $K_2$O $m^{-2}$ as a basal fertilizer dressing. It was compared with a low fertilizer treatment (LF) with only 4 g $P_2$ $O_{5}$ $m^{-2}$ as a basal dressing in the first year and no basal phosphorus fertilizer in the second year. Chopped rice straw was incorporated into the soil before the cropping season in both years. Fertilizer of 4 g N $m^{-2}$ was top-dressed at 15 days before heading in CON plots and 30 days before heading in LF plots in both years. Lodging was significantly less in LF than in CON plots, however, no rice straw effect was found in low fertilized condition. Grain yields in LF plots were reduced by 15-16% below those of CON plots. Lower yields in LF plots were associated with a reduced number of spikelets per unit area. However, big spikelet size was acquired in LF by 10 days earlier N top dressing than CON plots. A close relationship was found between spikelet numbers and N content of the plant at heading, and between grain yield or shoot dry weight and N content of the plant at maturity. Regardless of the fertilizer application methods, N use efficiency for the number of spikelets, final total dry matter and grain yield was essentially identical among fertilizer treatments. The reduced growth and yield in the LF plots resulted from low absorption of nitrogen. Conclusively, LIS can drastically reduce chemical fertilizer use and facilitate harvest operations by reducing lodging with some yield reduction..

• 한국농공학회논문집
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• 제53권4호
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• pp.49-57
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• 2011

The objective of this study was to experimentally investigate the feasibility of SRI (system of rice intensification) in Korean rice farming. Eight experimental plots of $5{\times}15$ m in size were prepared on an existing rice field of loam soil. Spacing was $30{\times}15$ cm (conventional treatment: CT), $30{\times}30$ cm, $40{\times}40$ cm and $50{\times}50$ cm, respectively. CT were flooded and SRI plots irrigated intermittently 3 to 5 day interval during cultivation. Organic matter content and pH of the soil were $2.5{\pm}0.03$ % and $6.1{\times}0.2$, respectively, before the cultivation. The highest number of tillers and height of the plant were measured at $50{\times}50$ cm plots. The height and number of tillers and height in $50{\times}50$ cm plots were 10 cm and 1.5 times more than CT. Average irrigation supply to SRI and CT was 243.2 mm and 547.3 mm, respectively. It meant that the reduction of irrigation water in SRI plots over CT was estimated to 55.6 %. Therefore SRI was concluded to have a good enough possibility to be applied in South Korea because it was proven to be more effective in reduction of irrigation water and crop cultivation compare to the CT.

• 한국토양비료학회지
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• 제51권2호
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• pp.79-89
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• 2018

Subsurface drip irrigation (SDI) system is considered one of the most effective methods for water application. A 2-year field study was conducted to investigate the effect of SDI systems with various dripline spacing (0.7 or 1.4 m) and position (under furrow or ridge) on soybean (Glycine max L.) production at a sandy-loam soil in Miryang, South Korea. For 2016-2017, average grain yield in SDI irrigated plots, $3.16Mg\;ha^{-1}$, was statistically greater than rainfed irrigated plot ($2.63Mg\;ha^{-1}$). Soybean grain yield averaged $3.25Mg\;ha^{-1}$ for the 0.7 m dripline spacing and $3.07Mg\;ha^{-1}$ for the 1.4 m spacing for the two-year period compared to a rainfed irrigated average of $2.63Mg\;ha^{-1}$ for the same period. Soybean treated with SDI system had significantly greater values of normalized difference vegetation index and stomatal conductance, indicating that soybean plants in SDI plots had greater photosynthetic and stomatal activity due to the higher water availability in soil. Irrigation water use efficiency (IWUE) was greatest in the plot of 0.7 m spacing installed under ridge position than any other plot across growing season. Average soil water content in plots with 0.7 m dripline spacing was $0.21m^3\;m^{-3}$ at 5 cm depth layer, which was 45% greater compared to the plots with 1.4 m spacing, even though the gross irrigation amounts were greater in 1.4 m spacing plots. It is concluded that wide dripline spacing (1.4 m) is probably the more economical installation design for SDI system compared to 0.7 m spacing in this study soil because the initial cost for dripline may be reduced with wide spacing design, even though the IWUE is greater in the plot of 0.7 m dripline spacing.

• Agricultural and Biosystems Engineering
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• 제7권1호
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• pp.18-26
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• 2006

In-field site-specific nitrogen (N) management increases crop yield, reduces N application to minimize the risk of nitrate contamination of ground water, and thus reduces farming cost. Real-time N sensing and fertilization is required for efficient N management. An 'on-the-go' site-specific N management system was developed and evaluated for the supplemental N application to com (Zea mays L.). This real-time N sensing and fertilization system monitored and assessed N fertilization needs using a vision-based spectral sensor and controlled the appropriate variable N rate according to N deficiency level estimated from spectral signature of crop canopies. Sensor inputs included ambient illumination, camera parameters, and image histogram of three spectral regions (red, green, and near-infrared). The real-time sensor-based supplemental N treatment improved crop N status and increased yield over most plots. The largest yield increase was achieved in plots with low initial N treatment combined with supplemental variable-rate application. Yield data for plots where N was applied the latest in the season resulted in a reduced impact on supplemental N. For plots with no supplemental N application, yield increased gradually with initial N treatment, but any N application more than 101 kg/ha had minimal impact on yield.

• 한국조경학회지
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• 제32권6호
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• pp.36-51
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• 2005

The purpose of this thesis is to analyse modem urbanization process and the morphological transformation of the urban tissues in Kunsan between the you 1899 and 2001, The method of this study is to investigate the transformation process of morphological elements such as plot structure, building layout, building facades, land use, exterior space structure and their use, with actual field surveys, the analysis of land registration maps in 1912, and various topological map. Morphological analysis on modern Kunsan is progressed by three steps-typo-morphological analysis of urban tissue in old-town area, interpretation of morphological process, and transformation process, of morphological structure in Japanese concession in view of plots system. As a result, it is found that there is cyclical relationship among the morphological transformation processes of morphological elements, plots, buildings, land-uses, and access space to buildings. From the view of town plan change, the period of restoration of war damage in 1950s and compressive growing period in 1960s have important meaning in the morphological process of old-town area. Particularly the first building plan and layout type together with plot form and structure is acted as the main factor to decide the subsequent plot transformation system, exterior space system and the particular streetscape in Kunsan.